Recent studies have indicated repeatedly that measures of infant visual attention are predictive of later intelligence. While stability in cognitive processes may indeed be operating temperamental characteristics mediate the relationship between infant cognitive ability and actual test performance. Furthermore, infant temperament, cognitive ability and the interface between the two domains may be affected by the surrounding familial temperament and cognitive level. The purpose of the proposed research is to explore the relationship between specific aspects of infant temperament and visual information processing. The research will also assess parental and sibling cognitive ability and temperament to determine the familial contribution to individual differences within the two domains and to the intersection between cognition and temperament. The study will involve 100 infants, their parents and their siblings. The infant's will be tested on a battery of visual information processing tasks that have been found in previous research to predict later intelligence. Temperament will be assessed using a videotaped laboratory assessment and temperament rating questionnaires. Each infant will be tested twice, once in the laboratory and once in their home, at both 6 and 9 months of age. Parent and siblings will be assessed on both cognitive and personality measures. Contributions of temperament to individual differences in infant information-processing will be empirically assessed as well as the effect of parental and sibling temperament and cognitive ability. Identification of the temperamental correlates of infant intelligence will aid in the diagnosis and treatment of infants suffering from cognitive deficits and may also further the goal of increased specificity for both diagnosis and intervention.